Manufacturers today have produced valves for the water and gas distribution fields which utilize a valve body and a rotatable valve element known in the trade as a "plug" or "key," the valve element having a flow passage therethrough. In such valve assemblies, especially where a tapered plug or key is used, it is often necessary to insert a tubular bushing into the open end of the valve body through which the plug or key is inserted, the purpose of the bushing being to conform the inside diameter of the valve body as close as possible to the inside diameter of the passage through the plug as well as to the inside diameter to the tubing or pipe to which the valve is to be connected. Additionally, the bushing is used as a backup for engaging or forming the flared end of a pipe when a coupling nut is used.
One type of valve construction such as heretofore described is shown in the U.S. Pat. No. 2,993,677, issued July 25, 1961, to John L. Ford. In this construction, a tubular bushing was press fitted into the open end of the valve body after insertion of the plug or key, the bushing being provided with an enlargement on the end portion extending outwardly of the body, the enlargement being arranged to abuttingly engage the end of the valve body to make a seal. When such a valve was assembled, and if there was subsequent damage to the valve plug or to the seal between the bushing and the body when the bushing was press fitted into the plug, then the valve could not be repaired but had to be thrown away. Additionally, if a bushing of different design or having a different interior diameter was needed, the whole assembled unit had to be discarded.
A more recent development in valve construction for the plug or key type valve included using a bushing which tapered inwardly from an enlarged head portion, the bushing being provided with an annular flange on its inner end of less diameter than the diameter of the opening in the valve body. Such a bushing was freely inserted into position in the valve body so that its flanged inner end was positioned opposite an annular groove provided on the interior wall of the opening in the valve body and, when in this position, the bushing was flared outwardly so that the flange was received in the groove in the valve body. This arrangement provided a rather loosely retained bushing with a seal ultimately being made by metal-to-metal contact between the enlarged outer end of the bushing and the end of the valve body or by an O-ring positioned between the enlarged outer end of the bushing and the end of the valve body when a coupling nut was used to retain the flared end of copper or plastic tubing. Since manufacturing tolerances require the groove in the valve body for receiving the flange of the bushing to be wide in comparison to the flange or retaining lip, there was a loose fit between the valve body and the bushing until a connection, such as a flared connection, had been made. This arrangement had the disadvantage in that it allowed dirt to get between the sealing surfaces and also between the bushing and the valve body prior to installation and, further, once the bushing had been installed in the valve body, it could not be removed and replaced for maintenance or other purposes, just as in the case of the valve construction shown in the aforementioned U.S. Pat. No. 2,993,667.
Heretofore, two tubular bodies have been coupled together by providing a resilient ring between the telescoping bodies, the resilient ring being received in opposed grooves, but the grooves were of such a shape as to either permanently retain the telescoping member together or they required the telescoping members to be tilted at an angle from one another to join or remove the same. In this respect, no thought was given to utilize the resilient ring as merely a provisional retaining means for holding the bushing in the valve body with its outer enlarged end tightly against the end of the valve body prior to the tightening of a coupling nut.